Subject: Re: [patch 1/2] fork_connector: add a fork connector
From: Ram <linuxram@us.ibm.com>
To: Guillaume Thouvenin <guillaume.thouvenin@bull.net>
Cc: Jesse Barnes <jbarnes@engr.sgi.com>,
       Evgeniy Polyakov <johnpol@2ka.mipt.ru>, Andrew Morton <akpm@osdl.org>,
       lkml <linux-kernel@vger.kernel.org>, Jay Lan <jlan@engr.sgi.com>,
       Erich Focht <efocht@hpce.nec.com>, Gerrit Huizenga <gh@us.ibm.com>,
       elsa-devel <elsa-devel@lists.sourceforge.net>
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Date: Tue, 22 Mar 2005 10:26:19 -0800
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On Mon, 2005-03-21 at 23:07, Guillaume Thouvenin wrote:
> On Mon, 2005-03-21 at 12:52 -0800, Ram wrote:
> >      If a bunch of applications are listening for fork events, 
> >      your patch allows any application to turn off the 
> >      fork event notification?  Is this the right behavior?
> 
> Yes it is. The main management is done by application so, if several
> applications are listening for fork events you need to choose which one
> will turn off the fork connector. 
> 
> I want to keep this turn on/off mechanism simple but if it's needed I
> can manage the variable "cn_fork_enable" as a counter. Thus the callback
> could be something like:
> 
> static void cn_fork_callback(void *data)
> {
>   int start; 
>   struct cn_msg *msg = (struct cn_msg *)data;
> 
>   if (cn_already_initialized && (msg->len == sizeof(cn_fork_enable))) {
>     memcpy(&start, msg->data, sizeof(cn_fork_enable));
>     if (start)
>       cn_fork_enable++;
>     else
>       cn_fork_enable > 0 ? cn_fork_enable-- : 0;
>   }
> }

I think a better way is:

   Providing a different connector channel called the administrator 
   channel which can be used only by a super-user, and gives you
   the ability to switch on or off any connector channel including the
   fork-connector channel.
 
   For lack of better term I am using the word 'channel' to mean
   something that carries events of particular type through the
   connector-infrastructure.
 
RP


> 
> 
> What do you think about this implementation? 
> 
> Guillaume
> 

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